Field of the Invention
The invention relates in general to a teaching device and a teaching method for a robotic arm, and more particularly to a teaching device and a teaching method for a robotic arm capable of remotely teaching the robotic arm to move by means of a vision device.
Description of the Related Art
Along with the rapid development in the manufacturing technologies, many production lines have replaced human labor with robotic arms to increase the speed of mass production, stabilize product quality and reduce labor cost. With the production configuration which allows one operator to monitor several robotic arms, production efficiency and market competiveness of the products can both be increased.
The robotic arm is normally moved at a high velocity to increase production efficiency. However, the robotic arm moving at a high velocity is hazardous to the operator operating the robotic arm within a short distance. Particularly, in a working environment with hazardous factors such as radiation, high temperature, high pressure or abnormal cold or heat or with unbearable conditions, how to remotely teach the robotic arm to operate such that the operator can be away from the hazardous working environment has become a prominent task for the industries.
For a robotic arm to be taught from a remote end, the robotic arm normally is equipped with a vision device such as a video recorder or a camera. The vision device shoots an image of the job site of the robotic arm and further transmits the image of the job site to a monitor disposed at a remote end and shows the image of the job site of the robotic arm on the remote-end monitor. The operator views the relative position between the robotic arm and the work piece shown on the monitor robotic arm, and operates a cabled or a wireless remote controller to teach the robotic arm to move, transport or assembly robotic arm the work piece to manufacture products.
For the robotic arm taught by means of remote control, the operation of the remote controller is restrictive, and it is inconvenient to carry the remote controller all the time. Of the prior art, the United States Patent No. US20110118877 “Robot system and method and computer-readable medium controlling the same” discloses a controlling method of the robot system to replace the conventional teaching method using a remote controller. According to the said United States Patent No. US20110118877, the moving direction of the robotic arm is taught according to the moving direction of a detected hand control gesture robotic arm, and the operation becomes more convenient.
According to the prior art, the vision device is merely disposed at the job site outside the robotic arm, and does not move along with the robotic arm. Therefore, when the remote-end monitor reduces the display frame, the operator can only see the overall working environment of the robotic arm but cannot clearly see the direction of the work piece and the relative position between the robotic arm and the work piece. Also, in the prior art, the movement of the robotic arm is controlled according to single-stage gestures. Such control based on single-stages gesture may easily cause the robotic arm to collide with the work piece, and is neither suitable for moving the robot hand to get close to the work piece nor suitable for the fine-tuning purpose such as adjusting the direction of the robot hand to grip the work piece. Therefore, the device and the method for remotely teaching the robotic arm to move still have many problems to resolve.